c - 错误 : variable ‘database’ has initializer but incomplete type?

Question

我有这个 typedef 结构和一个“构造函数”:

typedef struct database {
    char key;
    char value;
    struct database *next;
} Database;


Database db_createDb() {
    Database *db;
    db = malloc(sizeof(struct database));

    return *db;
}

我正在从主函数调用:

int main(int argc, char *argv[]) {
    Database database = db_createDb();
}

为什么我会收到错误消息“数据库有初始化程序但类型不完整”？

Answer 1

通过Database更改database，并保留指针以备后用:

Database * db_createDb() 
{
    Database *db;
    db = (Database *)malloc(sizeof(Database));

    return db;
}

int main(int argc, char *argv[])
{
    Database * database = db_createDb();

    ....
    free(database);

}